I've woken up from my Nightmare on C++ Street and have uploaded new
Rasterio, Fiona, and Shapely macosx wheels to PyPI. Use the pip requirement
specs below to get the latest and greatest compatible wheels.

rasterio==1.0a11

fiona==1.7.10.post1

shapely==1.6.2.post1

My Xcode command line tools were out of sync with my libraries, libc++abi.dylib
in particular. In the Xcode preferences there's an option to select versions
of the command line tools. On my home computer, I've got Xcode 7.2.1 and have
selected version 7.2.1 of the command line tools.

On my work computer, where I've been building the wheels, I somehow ended up
with Xcode 8.2.1 and version 9.0.0 of the command line tools. I've never even
seen this preference before, but do remember accepting a command line tools
upgrade from Apple's App Store a while back. Reverting to command line tools
version 8.2.1 cleared up the segmentation faults reported and studied in
https://github.com/sgillies/frs-wheel-builds/issues/20.

I hope this blog post finds the next person to trip over this Xcode and command
line tools mis-configuration.

Now I'm going to go back into PyPI and remove the broken binary wheels for
older versions, leaving only the source distributions.